I just got my new amp!! I'm dying to try it out, but I don't have a cab yet... So, the next best thing... What are the dangers of playing into headphones without having a cab plugged in (since my particular model doesn't have a headphone jack, i'd use the 'send' fx part)? I have a Genz Benz GBE400 (http://www.genzbenz.com/gbe400_series.htm) and I don't see anywhere in the manual or quick reference manual saying that it would be harmful... so should it be ok? Thanks!!